The invention is directed to a freewheel clutch with two coupling parts, namely an inner part and an outer part, as well as blocking pawls in between both parts pivotable by means of a control mechanism. The control mechanism comprises a frictional arrangement applying braking against rotation into an engaged position and a disengaged position with respect to both rotational directions. Two sets of blocking pawls are provided which are configured to transmit torque in opposite rotational directions and to freewheel in the respective other direction of rotation, wherein all blocking pawls are pivotably supported in recesses distributed across the circumference of one clutch part and can be brought into engagement with support recesses in the other clutch part.
Such a freewheel clutch is, for instance, known from DD-PS 1 39 154, DE-GM 1 888 456 and DE 34 26 108 A1. Herein, both sets of blocking pawls are controlled in such a way that the pivoting of the pawls to be moved into the disengaged position occurs by means of a shifting spring acted upon by a frictional arrangement or by a cam disk. The engagement of the blocking pawls occurs by the force of a compression spring assigned to each blocking pawl after appropriate penetrations in the shifting spring have been opened or the cam has been moved out of engagement with the corresponding locking pawl.
Furthermore, in a freewheeling arrangement known from DE-AS 16 25 730, a blocking pawl is provided, which is designed to have two arms and is pivotably supported in the driving part. One arm of the blocking pawl serves to provide a torque transmission in one direction of rotation and the other arm serves to provide a torque transmission in the other direction of rotation.
A braking mechanism has the effect that, depending upon the driving rotational direction, the twin armed blocking pawl is pivoted into the appropriate recess. For the reversal process from one rotational direction into the other rotational direction respectively, passage through a zero position is required where the blocking pawl is not in contact with any of the butt faces provided in the outer part for torque transmission. Thus, twice the travel in circumferential direction would be covered when passing from one torque transmittal direction to the other, than would be required in order to snap into one or the other torque transmittal direction from the zero position. Furthermore, the entire torque must be directed through the journal bearing of the locking pawl. The bearing must thus be sufficiently large in order to carry these forces.